1. Field of the Invention
The present invention generally relates to a punch press for machining a workpiece to produce a desired product by performing one or more punching operations. More particularly, the present invention relates to a method of automatically preparing a program for machining a workpiece with a punch press and also to an apparatus to be used for such a method.
2. Background and Material Information
Conventional punch press machines typically include a clamp device for holding a workpiece. Such a clamp device may be adapted for biaxial translation to align a desired spot or portion of the workpiece to be punched with a punch and a die prior to the actual punching operation.
An automatic programming apparatus is typically used for preparing a machining program for machining workpieces on a punch press of the type under consideration.
The operation of preparing a machining program normally proceeds in a manner as will be described hereinafter. First, an operator inputs graphic data to be used for the machining operation and selects one of the machining methods, registered in advance in the automatic programming apparatus, which is in the operator's view is the most appropriate for the graphic image the operator has entered. Then, the automatic programming apparatus prepares a machining program, by automatically selecting one or more metal tools, machining loci for the selected tools, a set of machining parameters and other factors. If the graphic image to be used for the machining operation contains any inappropriate portions that have to be modified for reasons that may include the lack of metal tools assignable to those portions, the operator manually carries out the necessary modifications, using techniques such as adding, replacing, and/or removing elements of the program, in order to produce a machining program that is free from deficiencies.
However, with such an automatic programming apparatus, it is difficult even for skilled operators, to say nothing of those who are unskilled, to prepare a machining program that is appropriate for a selected graphic image for machining in a short period of time. Additionally, when a program prepared by a skilled operator using such an automatic programming apparatus is compared with a program prepared by an unskilled person, the former produces products of a higher quality with a shorter machining time, providing a problem to be solved for an automatic programming apparatus.
The first problem arises from the fact that, if a machining method appropriate for the entered graphic image is selected out of a plurality of machining methods stored in advance in the automatic programming apparatus, the machining program prepared for the selected machining method often contains deficiencies that require corrections. As a result, the time for correcting operations to make the entire process of preparing a machining program good for the selected graphic image for machining is extremely time consuming.
On the other hand, the second problem is attributable to the fact that a skilled operator has a large amount of know-how in terms of the selection of appropriate metal tools and the generation of machining loci for the selected tools and other aspects necessary for improving the quality of the manufactured products. These skills reduce the manufacturing time as compared with an unskilled operator and the difference in the amount of know-how is reflected in the quality of the manufactured products and the machining time required for manufacturing the products.
Under these circumstances, there has long been a demand among those involved in this technological field for a new technological development that provides a better method for preparing a machining program for a given graphic image and for machining in a short period of time, regardless of the level of the skill of the operator. There is also a need for an improved method for preparing a machining program that is adapted for manufacturing a punched product according to the prepared machining program and meeting a required level in terms of quality and machining time also regardless of the level of the skill of the operator.